The wonder of mud

While this sounds like a bit of a strange and potentially boring story, it’s probably one of the most important ones I will ever tell.

In this feature, I’ll be explaining why soil is so important to the food system we all rely on, and the threats that it faces in present times. Hopefully, after reading this, you’ll be inspired to think more about how magical and essential soil is with the next bite of food you take.

WHAT IS SOIL?

We all know that soil is the stuff on the ground that plants grow in. With the exception of fish, it is the beginning of all of our sources of food.

It is mostly made up of three mineral elements: clay, sand and silt, the ratio of which will affect the colour and texture of the soil. It also contains organic matter, which is basically decomposing plants and animals. This organic matter is like fuel to the soil, filling it with nutrients which new plants need to grow. Soil without nutrients is useless, like a car without a fuel tank – it looks the same from a distance, but struggles to function.

HOW DO OUR FOOD SYSTEMS RELY ON IT?

The vast majority of our food comes from plants. Even our meat has to eat plants, or other animals which have fed on other animals, or plants. See what I’m saying?! Soil plays a major role in this chain, providing:

Nutrients: All plants need nutrients, and the best place to get these nutrients is from soil. Nature is clever – its eco systems are created in such a way that soil is continually fertilised by any decomposing plants and animals that fall onto it (by “fertilised” we basically mean “fed with nutrients”). These nutrients are then held in the soil to feed future generations of plants and animals, and so on. There are millions of organisms within healthy soil, which help break down plant and animal matter into nutrients. Most of these are not even visible to the human eye, such as bacteria, fungus and many other tiny organisms.

Stability: All living plants have roots which bed into the soil like wires into a plug socket. As well as being the source of food and water for the plant, they also act as a foundation, keeping the plant where it is and giving it stability. Usually two-thirds of a plant is underground, in the roots.

Water: The structure of soil also carries out one other super-important function – it holds and stores water, which is vital to all living plants and animals on Earth. Soil’s ability to store water depends on the type of soil, the organic matter within it, and the root system taking hold in it.

WHY IS SOIL CHANGING?

Without human intervention, soil systems work beautifully by themselves, with soil, plants and animals all co-operating and feeding each other. You only have to visit an untouched rainforest, a national park or woodland to see this in action.

Yet soil systems started to change significantly when humans came along and started farming the land. Remember that farming is a man-made process, and not something that happens in nature. It is where we manipulate the land, soil, plants and animals to provide food or fuel for ourselves or livestock.

Left to its own devices, soil will hold a mixture of plants that all work together and feed the soil with different nutrients. This is known as “bio-diversity”. Often in farming, we decide to grow huge amounts of just one particular plant at a time. When we plough the land and plant one variety over and over, the soil loses its diversity of nutrients and can become starved.

The common solution to starved soil is to add chemical fertilisers to feed the plants instead. While this may sound like a good idea, it’s pretty unsustainable. Chemical fertilisers to plants are like sweets to a small child: the soil gets loads of energy, the plants go a bit crazy, but the system is not healthy in the long-term. It prevents roots from growing or taking hold properly as the plants get their energy from chemicals instead.

WHAT HAPPENS WHEN SOIL IS NEGLECTED?

So by using chemical fertilisers, roots do not grow as long or as strongly as they should, and by farming just one or two types of plants, soil does not naturally get the mix of nutrients it needs to stay healthy. This contributes to something called “soil erosion”, where the soil becomes weak and cannot hold water. Therefore, when it rains, the water simply runs straight off, and can even take some of the soil with it. The weakening of soils is known to be one of the largest causes of flooding, where rain washes straight into rivers, raising the height of the river and causing extensive damage to homes and land.

Genetic engineering is extending this problem further by adding excess chemicals to soil. Genetically modified (GMO) plants are developed to withstand even higher levels of chemicals, allowing even more fertilisers to be added to the soil. Great news for people selling chemical fertilisers, who are often the same people that sell the genetically engineered plant seeds. Funny, that.

WHAT WE CAN DO TO HELP

Essentially, the best thing we can do to help is to buy products which support sustainable farming practices and recognise soil as a valuable part of sustainable farming. The LEAF mark is something you can look out for on products in supermarkets. This shows that the farms the product came from practise “integrated farm management”, which means that they carefully manage the diversity and quality of their soil.

Certified organic products are also a great way of supporting better soil management, as they prohibit the use of chemical fertilisers, meaning that farmers have to rely on more sustainable ways of managing soil. Look out for organic logos on produce, meat and dairy.

Another alternative for meat from systems which truly care for soil quality is to look out for products carrying the Pasture For Life label. This meat comes from farms where animals live in harmony with pasture and soil, and that do not use any chemicals on their land.

About the author

Daniel Nowland has a scientific degree in food quality, and is Jamie’s in-house expert on all things food and farming related. He spends much of his time on farms and in factories all over the world, working with Jamie on developing and raising standards.